Blender to Godot scale
In my experience, it is best to get the model as &quot;right&quot; as possible as early as possible. So I'd do all the scaling in Blender before exporting.
To do so, it is best to set Blender scale units to &quot;metric&quot;

(if not already so) and then scale everything to real-world size.
The most important step is now to

apply all transformations. Then, your exported geometry should come into Godot the right size so your physics will be all correct.
As for your concern that blender physics could not handle real world sizes: This may be somewhat true if the real world objects are very large. If you want the truck to behave realistically, it should have its real size.